CuO-based nanoplatelets for humidity sensing application

Abstract

Determination and monitoring of humidity level is of great importance because water is one of essential components of the living organisms and materials used by people. Metal oxides are the most popular materials used as sensing elements for humidity sensors, due to their excellent thermal and environmental stability, high mechanical strength, wide range of working temperature, low fabrication cost and robustness in practical applications. Humidity sensing ability of metal oxide based ceramic materials can be enhanced by doping with metal cations. In this work, we present hydrothermal method for preparation of pure and Mgdoped CuO nanoplatelets and investigate their sensing properties towards humidity. The proposed method involves autoclaving of copper(II)-acetate solution under autogenous pressure in alkaline conditions, with different concentrations of Mgdopant (0, 2.5, 5 and 10 mol%). We have performed thorough structural and optical investigations of as synthesized material (TEM, XRD, SAED, UV-VIS-NIR). Furthermore, we have processed obtained powders into functional thick films using doctor blade technique, and their sensing properties were tested in wide range of temperatures (25, 50, 75 °C) and relative humidities (40–90%), resulting with strong response and promising response/recovery times.